The present invention relates to a device for preparing a photographic liquid which is to be applied in the manufacture of a photographic photosensitive material, and particularly relates to a photographic liquid preparation device which is effective in applying multiple layers of photographic liquids at the same time.
A general type of liquid preparation device was disclosed in the Japanese Patent Application (OPI) No. 74715/81 (the term "OPI" as used herein means an "unexamined published application").
In the manufacture of a photographic photosensitive material, multiple layers of different liquids need to be applied on top of one another on a carrier made of a plastic film of triacetyl cellulose, polyethylene terephthalate or the like, or made of laminated paper. For a color-sensitive material, for example, the layers of such applied liquids include photosensitive emulsion layers sensitive to red, blue and green light, respectively, and are of two or three different sensitivities, high, medium and low sensitivities. Also included is an intermediate layer serves as an optical filter, a protective layer which enhances the physical strength of the surface of the material, and so forth. Presently, in current color film ten or more layers are applied in all.
To apply such a large number of liquids, an apparatus which can apply multiple layers simultaneously is used in order to enhance productivity. Usually, multiple liquids are applied at the same time. For that purpose, the plural different liquids need to be simultaneously prepared and supplied to an application process in order to manufacture a photographic photosensitive material. Each of the liquids is produced by adding various kinds of chemicals to a raw emulsion or an emulsified substance as the main constituent of the liquid, mixing them and stirring them. The added chemicals include an acid or alkali for pH adjustment, a viscosity increasing agent for viscosity adjustment, a surface active agent for surface tension adjustment, and so forth. Many of the chemicals are added at different mixture ratios for different liquids.
In a conventional device for preparing a photographic liquid which is to be subsequently applied, a single pipe is laid from each chemical storage tank (m kinds in all) to each liquid preparation tank (n kinds in all) and fitted with a measuring unit, a control unit, a valve and so forth. Therefore, n.times.m sets of pipes, measuring units, control units, valves and so forth are provided in all in the conventional device.
As a result, the conventional device has problems mentioned below.
(1) Since there are a large number of the pipes, the measuring units, the control units, the valves and so forth, the cost of the equipment is high. PA1 (2) Maintenance of the device requires a large number of steps. PA1 (3) The reliability of the equipment as a whole is low.